Sequenom, Inc announced new data from a collaborative project with The Chinese University of Hong Kong, published this week in the early edition of the Proceedings of the National Academy of Sciences, that demonstrate its innovative, next-generation, noninvasive prenatal diagnostic technology accurately quantified maternal plasma DNA sequences for fetal Trisomy 21, or Down syndrome, based on samples taken from women in the first and second trimesters of pregnancy. These data are the first to suggest that this future approach, based on massively parallel genomic DNA sequencing, can be effective in women who had not previously undergone invasive procedures.
This study used massively parallel genomic sequencing to quantify maternal plasma DNA sequences for the noninvasive prenatal detection of Down syndrome, assessing samples from 28 women in the first and second trimesters of pregnancy. All 14 Down syndrome fetuses and normal fetuses were correctly identified at these early stages.
"Current invasive methods for diagnosing Down syndrome in pregnancy have documented risks associated with such procedures. Our new study using massively parallel genomic DNA sequencing represents a next-generation' technology for noninvasive, safe testing of Down syndrome. This is the first study to show that this approach can be used for the detection of Down syndrome in both the first and second trimesters, based on a rigorously controlled clinical cohort in which the pregnant women with fetuses affected by Trisomy 21 and those with normal fetuses were matched in gestational age, and in which most of the studied subjects had not previously undergone an invasive procedure. The latter point is important as it shows that the method would truly work in the noninvasive prenatal diagnostic scenario. This study also employs a novel data analysis algorithm which has achieved an unprecedented clear separation of the Trisomy and normal samples," stated Dennis Lo, co-author of the study, and Li Ka Shing, Professor of Medicine at The Chinese University of Hong Kong. "While this new approach is several years away as a commercially viable test, we believe that massively parallel genomic sequencing of DNA in maternal plasma may offer a complementary approach to the RNA SNP allelic ratio approach that we reported last year for Trisomy 21 detection. The two approaches have performance and cost profiles which would potentially be synergistic to one another."
Sequenom licensed the exclusive rights to the massively parallel genomic DNA sequencing technology featured in this study from The Chinese University of Hong Kong in September 2008.
"Screening tests currently available for early detection of Down syndrome and other chromosomal disorders are associated with a relatively high rate of inaccuracy, which can result in an overlooked abnormality or, in the case of false positive results, unnecessary invasive and risky procedures," stated Harry Stylli, president and chief executive officer of Sequenom. "Systems to support DNA sequencing like massively parallel genomic sequencing or shotgun sequencing are currently limited to the academic setting due to scalability limitations and high cost, therefore practical applications are several years from commercialization. We find the data reported by Dr Lo and associates to be very compelling and, while we continue to evaluate other promising approaches, Sequenom licensed this technology several months ago because we believe massively parallel genomic sequencing is a promising approach to prenatal diagnostics that may offer a future extension to our SEQureDx prenatal diagnostics franchise. Even though this technology is years away from the clinic, we expect that our current RNA SNP allelic ratio technology - which is the basis for the Down syndrome test we expect to launch in June 2009 - will represent a major step forward in maternal and fetal testing."
Current screening technology for Down syndrome includes serum marker analysis, such as the quad screen and first trimester combined screening that employs both serum marker testing and nuchal translucency. These approaches have detection or sensitivity rates of 80 per cent and 85 per cent respectively, which means between 15 per cent and 20 per cent of all Down syndrome-affected pregnancies will not be identified as needing further evaluation. In addition, these approaches also have false positive rates between 5 per cent and 10 per cent, resulting in hundreds of thousands of unnecessary, highly invasive CVS or amniocentesis procedures. These invasive procedures, which are used to determine whether the fetus has Down syndrome, carry a risk of miscarriage in the range of one-in-100 to one-in-300.
Sequenom's commercial opportunities in prenatal diagnostics are built upon its SEQureDx technologies and are enabled by the pioneering inventions and associated intellectual property rights that it has exclusively licensed from Isis Innovation Ltd, the technology transfer company of the University of Oxford, as well as The Chinese University of Hong Kong.
Sequenom is committed to providing the best genetic analysis products that translate the results of genomic science into solutions for noninvasive prenatal diagnostics, biomedical research, translational research and molecular medicine applications.